1. Field of the Invention
The present invention relates to a windshield wiping device for wiping a windshield of a vehicle or the like.
2. Description of Related Art
As such a windshield wiping device installed on the vehicle, a step-less intermittent type of windshield wiping device is known. In this wiping device, under condition that the vehicle is energized, that is, when a key switch (or an ignition switch) occupies either one of an "IGN (ignition)" position and an "ACC (accessories)" position, an operation of a wiper can be controlled by manipulating a wiper switch disposed in the vicinity of a driver's seat. When the wiper switch is at an "OFF" position, the operation of the wiper is stopped. In case of an "INT (intermittent)" position of the wiper switch, the wiper is intermittently operated at intervals established by an intermittent period adjusting volume switch. At a "LO (low)" position of the wiper switch, the wiper is driven slowly. Conversely, at a "HI (high)" position of the wiper switch, the wiper is driven at a high speed in comparison with a speed of the wiper in case of the "LO" position of the wiper switch.
Furthermore, an automatic intermittent and raindrop-sensitive type of windshield wiping device is also known. Detecting the intensity of rain by a raindrop sensor attached on the vehicle, the windshield wiping device of this kind is capable of changing an intermittent period of the wiper's operation automatically in accordance with the detected intensity of rain. Also in operation of the windshield wiping device, an operational mode of the wiper is controlled by manipulating a wiper switch which can occupy each of the positions of "OFF", "AUTO (automatic)", "LO" and "HI". Only when the wiper switch occupies the "AUTO" position, the intermittent period of the wiper's operation is automatically adjusted in accordance with the intensity of rain. Therefore, in view of avoiding the driver's burdensome operations during driving, the driver usually uses the windshield wiping device while positioning the wiper switch at the "AUTO" position.
In the above-mentioned step-less intermittent type of windshield wiping device, however, there is a case that the vehicle is again energized (key switch: ACC or IGN) while the wiper switch is not put back in the "OFF" position after finishing the previous driving. In such a case, the wiper would be actuated against the driver's will, corresponding to the position of the wiper switch at the moment.
In the above-mentioned automatic intermittent and raindrop-sensitive type of windshield wiping device, if the vehicle is energized in the rain on condition that the wiper switch still occupies "AUTO" position, there is a possibility that the wiper is operated in a manner apart from the driver's will. Additionally, if an alien substance exists on a wiping area of the wiper, the substance itself, the windshield, the vehicle or the like will be damaged.
Additionally, in the automatic intermittent and raindrop-sensitive type of windshield wiping device, if the vehicle is washed in an automatic car-washing machine while the wiper switch is still being at the "AUTO" position, then the rain-drop sensor will detect the water for washing to operate the wiper, so that washing instruments, the wiper and the vehicle are damaged unfortunately.